Simulation of physics phenomena is an indispensable part of experimental studies. Undergraduate and postgraduate physics students are often introduced to the simulation of various phenomena as one of the most important pedagogical tools. In this document, we demonstrate the simulations of the two-body decay of a particle and equilibrium states in…

A loop-the-loop experiment usually involves a ball rolling around a vertical loop. A different version of the experiment is described where a nut was allowed to slide around a vertical loop. In both experiments there is a large decrease in kinetic energy when the ball or the nut first enters the loop.

Experimental results are presented concerning the motion of a ball that bounces up an incline a few times then bounces back down again. The number of bounces up the incline is typically small since the speed of the ball in a direction parallel to the incline decreases rapidly, not only during each bounce but also while the ball is in the air. The…

We consider the operation of the hypothetical mechanical vehicle driven by an engine powered by small rockets introduced by P D Hanstead in the inaugural volume of this journal. Hanstead arrived at three contradictory conclusions regarding the change in velocity should some of the rockets malfunction at a particular time. This thought experiment…

If a ball rolls in a circular path on a horizontal surface at constant speed then its horizontal rotation axis changes direction with time. A simple experiment is presented showing that the torque applied to the ball is equal to the rate of change of its angular momentum, even though the magnitudes of its angular velocity and angular momentum…

If an empty coffee cup is spun on a horizontal surface about a vertical axis in an anti-clockwise direction, then the whole cup rotates slowly backwards, in a clockwise direction, about a vertical axis located outside the cup. Clues to this curious behaviour are presented by comparing it with other spinning objects.

Experimental results are presented on the collision of a superball with two different wood blocks. The results are in reasonable agreement with a simple collision model where kinetic energy is conserved, but better agreement is obtained if a small loss of kinetic energy is assumed, as observed. The physics is slightly more complicated than the…

A simple experiment for students is to measure the coefficient of restitution (COR) for a vertical bounce on a horizontal surface. In this paper, measurements are presented of the COR for a tennis ball bouncing at an oblique angle on a horizontal surface. Changes in the horizontal and rotation speeds were also measured, by filming the bounce with…

A significant goal when teaching at the secondary education level is to present the generality of the procedures that are being used to describe a wide range of different physical phenomena. However, this approach is abandoned by physics instructors in many cases since the general mathematical background needed to present the above generality is…

Measurements and calculations are presented showing how the trajectory of an object sliding across an inclined plane varies with the launch and incline angles. The trajectory depends on the magnitude and direction of the sliding friction force. The experiment is easy to set up, can be analysed using a video camera, and would be suitable for a…

Calculations are presented showing that the usual 'faster than g' demonstration has a surprising property. That is, a rod hinged at its bottom end rotates at an exponentially increasing rate until it falls with maximum vertical acceleration, unlike an object that falls freely by gravity alone. If the rod is hinged at its top end and released from…

The purpose of this publication is to present a novel approach to the demonstration of the Dzhanibekov effect. The main idea of our version is to use a lightweight spinning top of a spherical external form but distinct principal moments of inertia floating in the upward flow of air. As a result, the Dzhanibekov effect can be easily demonstrated…

We study the variation of the apparent weight of an object with height above the surface of a planet with a (buoyant) atmosphere. Interestingly, this variation depends on two competing factors--the reduced gravitational acceleration (which acts to reduce the weight with increasing height) and the reduced buoyancy force in the progressively less…

Diffraction refers to a kind of optical phenomena which occurs when light approaches an element (object or aperture) whose features are in the range of the illuminating wavelength (small apertures, sharp edges). It can be explained by means of the undulatory nature of light or also geometrically by using simple ray optics. Diffraction phenomena…

We outline the physics involved in the use of scanning electron microscopy (SEM) and modernise the usual textbook treatment by explaining how one can now obtain high-quality images with non-conductive specimens. As a concrete example of an application in biology, we provide several magnification series of a flea obtained using SEM.